Method and system for determination and classification of intoxicants in breath samples facilitated by a user interaction scheme - Patent Application 20070122999

Abstract

The present invention relates to a breath analysis system and method, and in particular to a breath analysis system and method configured to provide tracer-assisted determination and classification of the presence of intoxicants in breath, facilitated by a user interaction scheme. If a determination cannot be made in an initial compliance mode of operation, an interaction mode is initiated and the user is prompted step-by-step to perform actions that will facilitate the classification. An action compliance value, which represents how well the user complies with the issued actions / instructions, is determined and used to select an action.

Description

[Technical Field]

[0001] The present invention relates to a breath analysis system and method, and in particular to a breath analysis system and method configured to provide tracer-assisted determination and classification of the presence of intoxicating substances in exhaled breath facilitated by a user interaction scheme. [Background technology]

[0002] Breath analysis devices are becoming increasingly common in vehicles, in no small part as a means of detecting and preventing driving under the influence of intoxicating substances, particularly ethyl alcohol (ethanol). A breath analysis device may be a stand-alone, or even handheld, unit that provides a measurement of the content of one or more substances in the driver's breath. Alternatively, a breath analysis device may be part of a system that further includes equipment for identifying the driver and / or immobilizing the vehicle. Such breath analysis devices are typically permanently mounted in the vehicle and may, for example, be an integral part of the dashboard. A breath analysis device may also be a fixed system used to control access to work areas, fleet garages, etc.

[0003] It is important to provide a breath analyzer that is suitably sensitive, reliable, and provides a reasonably fast analysis. This is particularly true when the breath analysis device must be able to detect multiple substances and must not be hindered by changes in humidity, CO2 content, etc. Breath analysis devices that meet these requirements are described, for example, in U.S. Patent No. 7,919,754 and U.S. Patent No. 9,746,454, which are incorporated herein by reference.

[0004] The breath analysis device may be part of a system that further includes a device for identifying the driver and / or immobilizing the vehicle, such as a so-called "alcolock." Such breath analysis devices are typically permanently installed in the vehicle and may be an integral part of the dashboard, for example, and may be connected to the vehicle's control system. Alcolocks are widely used in offender programs as a mandatory accessory for the rehabilitation of car owners convicted of drunk driving. In addition, similar systems and devices are used in commercial vehicles such as buses, taxis, and trains. However, it is clear that these systems will soon become commonplace in private vehicles as well, and possibly even mandatory in at least some countries and regions.

[0005] To date, the most common approach to vehicle-mounted breath testing devices is the use of a mouthpiece, into which the user must empty their airway after a deep inhalation. This approach is called active detection. To ensure an accurate determination, the user must deliver a forced exhalation at nearly their full lung capacity. This requires significant time and effort, especially for people with low lung capacity. In addition, the mouthpiece or parts of the mouthpiece are often made of disposable plastic for hygiene reasons. This requires cumbersome handling, and the use of a large amount of disposable plastic that would result if an alcolock were required is problematic from an environmental perspective.

[0006] An alternative approach, called non-contact detection, does not use a mouthpiece; instead, a breath testing device typically receives a mixture of exhaled breath and ambient air, and the detection of intoxicating substances is determined from a breath sample taken during normal breathing. Detection can be truly passive, requiring no user action, such as while the user is performing a vehicle's normal starting routine. Alternatively, the user can be instructed to perform a specific action intended to facilitate the detection process, such as exhaling toward an air inlet. One challenge with non-contact detection is that low concentrations of substances can be detected and analyzed even when the user is instructed to exhale in a specific direction. An established method is to use a tracer gas, typically carbon dioxide or water vapor, that is always present in exhaled breath in highly predictable amounts to both trigger analysis of the target substance and facilitate the determination of the target substance concentration value. However, making non-contact detection work satisfactorily in real-life scenarios has proven difficult. Even if the data indicating the presence or absence of an intoxicating substance is ultimately analyzed correctly, the time required for such classification is unacceptably long in vehicles, e.g., causing an alcolock to stop the vehicle until approval is given. Therefore, there is a need for systems and methods that provide faster and more reliable feedback to the user / driver, and in particular, measurement errors must be handled in an effective manner.

[0007] Co-pending application SE2050105-2, by the same applicant as the present invention, discloses a breath analysis system and method configured to provide rapid tracer-assisted classification of the presence of intoxicating substances in breath above a limit concentration, and providing a user with status regarding the progress of the classification. SE2050105-2 is incorporated herein by reference.

[0008] U.S. Patent No. 7,736,903 discloses a system and method for passive detection of alcohol using a first tracer and a second tracer, and a first time period and a second time period to compensate for environmental variations. Response times for such systems are typically several minutes, which is considered too slow for practical use in both automotive and other applications.

[0009] U.S. Patent No. 8,377,705 discloses adding another tracer, water vapor, and another detection mode in which the ethanol and tracer signals are measured at a first time point and a second time point distinct from the first time point, but there is no mention of how to avoid or manage measurement errors, and response time appears to be an issue with this system / method as well.

[0010] U.S. Patent Application Publication No. 2020 / 101982 relates to a breath alcohol sensor / analyzer, a microphone / speech recognition unit, and a loudspeaker / speech synthesizer. The speech synthesizer generates questions that are answered orally by the subject, thereby generating an airflow that can be detected by the breath analyzer. The analysis results determine the drivability of the vehicle. Problems related to ambiguous or invalid sensor data remain. Such ambiguity may be caused by signal interference, out-of-range environmental conditions, technical errors, or a less-cooperative subject. The latter cause is believed to be dominant.

[0011] Therefore, there remains a need for improved breath analysis equipment in vehicles to achieve widespread acceptance of this technology. Most importantly, the test should be quick and reliable for a driver / user who is sober and follows instructions on how to administer the test. Ideally, the test should not add any manual steps for a sober and compliant driver / user and should not introduce any time delays when starting the vehicle. Summary of the Invention [Problem to be solved by the invention]

[0012] It is an object of the present invention to provide a breath analysis system and method of operation that overcomes the shortcomings of prior art passive detection systems. [Means for solving the problem]

[0013] This is achieved by a method according to claim 1 and a breath analysis system according to claim 13.

[0014] According to one aspect of the present invention, there is provided a method for operating a breath analysis system to determine a restriction level for a user performing a specified task based on an analysis of the concentration of an intoxicating substance in the user's exhaled breath and the user's behavior, the method including a compliance mode of operation and an interactive mode of operation, the method using a set of predetermined restriction levels and a set of predetermined actions. The compliance mode is sampling a signal representative of a local concentration of the intoxicating substance, analyzing the results of the sampling, and determining from the results of the analysis whether the user's breath concentration of the intoxicating substance can be classified with a required level of accuracy and precision; If classification is determined to be feasible, determining an intoxicant breath concentration; comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; Includes. If it is determined that classification is not possible to perform, the method enters an interactive mode of operation, which includes: issuing a selected action from a set of predetermined actions to the user, the selection of the instruction being based on a session history log and an action adherence value, the session history log including information about issued selected actions in the current interactive mode session and corresponding results of the issued selected actions, the action adherence value being a value determined from the results of the issued selected actions, and the results of the issued selected actions being an improved determination of intoxicant breath concentration or an output from the secondary sensor; sampling a signal representative of a local concentration of the intoxicating substance, analyzing the results of the sampling, and determining from the results of the analysis whether the user's breath concentration of the intoxicating substance can be classified with a required level of accuracy and precision; If classification is determined to be possible, determining an intoxicant breath concentration; comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; If classification is deemed impossible, determining an action adherence value based on an analysis of how well the user adheres to the issued selected action; updating a session history log, the session history log including at least information regarding which actions of a predetermined set of actions have been issued; Repeating the steps in interactive mode until a regulatory level is established. Includes: Alternatively, or in combination, the steps are repeated until a predetermined maximum period is reached.

[0015] According to one embodiment of the method, the set of restriction levels includes a plurality of restriction levels representing increasing restrictions on the drivability of the vehicle, and may include one or more of restriction levels corresponding to vehicle settings such as driving without restrictions, driving with issued warnings, limited drivability, and ignition locked.

[0016] According to one embodiment of the method, the set of predetermined actions includes at least one of the following subsets: an attention action, an instruction action, a request for action, and a warning action. The attention action may include activating a visual attractor.

[0017] According to one embodiment of the method, the dialogue unit is used by the breath analysis system to communicate the selected action to the user.

[0018] According to one embodiment of the method, the steps include a further step that occurs when the selected action is issued, the further step including receiving an acknowledgement from the user acknowledging understanding and consent to the selected action.

[0019] According to one embodiment of the method, the action compliance value is based on an analysis of whether the measurement of the intoxicating substance has improved the likelihood of classification with a required level of accuracy and precision. Alternatively, or in combination, the determined action compliance value is based at least in part on input provided by the secondary detection unit.

[0020] According to one aspect of the present invention, Interactive mode behavior is issuing a selected action from a set of predetermined actions to the user, wherein the selection of the instruction is based on the session history log and the action adherence value, and the selected action is issued via a visual attractor and / or an interaction unit; sampling a signal from the breath measuring unit representative of the local concentration of the intoxicating substance, analyzing the results of the sampling, and determining from the results of the analysis whether the breath concentration of the intoxicating substance of the user can be classified with a required level of accuracy and precision; If it is determined that classification can be performed with the required level of accuracy and precision, determining an intoxicant breath concentration; comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; If classification is deemed impossible, determining an action compliance value based on an analysis of how well the user complied with the issued selected action using input from at least one secondary detection unit, the secondary detection unit providing other information about the user different from the breath measurement unit; updating a session history log, the session history log including information about which actions of a predetermined set of actions have been issued; repeating the steps of the interactive mode until a restriction level is established or until a predetermined maximum period is reached; Includes:

[0021] According to one embodiment of the method, issuing the selected action includes the breath analysis system using one or a combination of interaction units such as a loudspeaker and a display.

[0022] According to one embodiment of the method, determining the action compliance value after the selected action is issued includes using one or a combination of secondary detection units such as a camera combined with image analysis capabilities, a microphone combined with voice recognition capabilities, an IR sensor, and a seat occupancy sensor.

[0023] According to one aspect of the present invention, there is provided a method, a breath analysis system, comprising a breath measurement unit, at least one visual attractant, at least one secondary detection unit, at least one interaction unit, and a CPU. The breath analysis system is in a compliance mode, and comprises: sampling a signal from the breath measuring unit representative of the local concentration of the intoxicating substance, analysing the results of the sampling, and determining from the results of the analysis whether the breath concentration of the intoxicating substance of the user can be classified with a required level of accuracy and precision; If classification is determined to be feasible, determining an intoxicant breath concentration; comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; to provide a compliance mode, including If it is determined that classification is not possible, an interactive mode of operation is performed, issuing a selected action from a set of predetermined actions to the user, wherein the selection of the instruction is based on the session history log and the action adherence value, and the selected action is issued via a visual attractor and / or an interaction unit; sampling a signal from the breath measuring unit representative of the local concentration of the intoxicating substance, analyzing the results of the sampling, and determining from the results of the analysis whether the breath concentration of the intoxicating substance of the user can be classified with a required level of accuracy and precision; If it is determined that classification can be performed with the required level of accuracy and precision, determining an intoxicant breath concentration; comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; If classification is deemed impossible, determining an action compliance value based on an analysis of how well the user complied with the issued selected action using input from at least one secondary detection unit, the secondary detection unit providing other information about the user different from the breath measurement unit; updating a session history log, the session history log including information about which actions of a predetermined set of actions have been issued; repeating the steps of the interactive mode until a restriction level is established or until a predetermined maximum period is reached; to provide interactive mode behavior, including It is composed.

[0024] The present invention provides a breath analysis method and system that significantly shortens the time period for reliable classification in the majority of testing situations, and in particular, the test is quick and convenient for a sober user who complies with the given instructions.

[0025] One advantage provided by the present invention is that the system makes extensive use of equipment that is often already provided in the vehicle, such as touch screens, voice recognition systems, and various sensors / detectors.

[0026] Another advantage is that the method provides an expansion of the actions that can be offered to the user, such as providing a warning to a user that is not necessarily above the legal limit for an intoxicating substance but still requires caution. The warning can be given in a manner that is also communicated to occupants in the vehicle.

[0027] One further advantage is that as the actions required of the user are progressively increased in complexity, the time required to perform the actions and / or analyze the results is also progressively increased, so that complex and time-consuming actions are used only when actually needed.

[0028] In the following, the invention will be described in more detail, by way of example only, in connection with non-limiting embodiments thereof, and reference will be made to the accompanying drawings, in which: FIG. [Brief explanation of the drawings]

[0029] [Figure 1a] 1 is a schematic diagram of a breath analysis device according to the present invention; [Figure 1b] 1 is a schematic diagram of a system according to the present invention implemented in the dashboard of a vehicle; [Figure 2] 1 is a flow chart of a method according to the present invention; [Figure 3] 1 is a graph illustrating how the method and system according to the present invention provides the results of an analysis in relation to the time since the start of the process. DETAILED DESCRIPTION OF THE INVENTION

[0030] For example, terms such as "top," "bottom," "upper," "lower," "below," "above," etc. are used to refer to the shape of embodiments of the invention as shown in the drawings and / or during normal operation of a device / devices, and are not intended to limit the invention in any manner.

[0031] Classification in this context means determining whether a subject's breath concentration of an intoxicating substance, such as ethyl alcohol, is above or below (below) a predefined limit.

[0032] The tracer is a physiological substance inherently associated with exhaled breath, such as carbon dioxide or water vapor.

[0033] Baseline refers to the signal level corresponding to the concentration of intoxicant or tracer to which other instantaneous signal values ​​are referenced. Offset error is the deviation from the baseline.

[0034] The concentration peak is defined by a maximum in the measured concentration versus time, with an increase in concentration before the peak maximum and then a decrease thereafter.

[0035] In the following, the breath analysis system and method for determining and classifying concentrations of intoxicating substances will be primarily described as a vehicle-mounted and integrated system. This is an exemplary embodiment. However, as will be realized by those skilled in the art, the system and method may be implemented in other ways, such as, but not limited to, stand-alone systems used in restricted work areas, entrances to vehicle fleet parking lots, etc. Modifications for such implementations will be apparent to those skilled in the art in light of this description.

[0036] The breath analysis system and method according to the present invention will be primarily described as a vehicle-mounted non-contact detection system, which represents an important embodiment of the present invention. As will be realized by those skilled in the art, the present teachings are equally relevant to stand-alone systems, such as systems at entrances to work areas, fleet depots, etc. According to some embodiments described below, the system and method according to the present invention may be a combination of a non-contact detection system and an active system using a mouthpiece to sample the breath sample.

[0037] A major concern for the general acceptance of widespread or even mandatory intoxication testing, for example in vehicles, is the time required to administer the test and / or whether the test is inconvenient for drivers. While intoxicated drivers are a significant problem, it must also be recognized that the majority of drivers are not intoxicated, and therefore intoxication testing administered in vehicles can be expected to detect no illegal amounts of intoxicants in the vast majority of test cases. Estimates by Swedish traffic authorities indicate that 99.8% of drivers exhibit alcohol concentrations below the legal limit. While the exact numbers vary in different countries / regions, typically, well below 1% of all tests are expected to result in concentrations above the legal limit. A breath analysis system that is fast and convenient for a clearly sober user who complies with given instructions, but that takes more time if early indications indicate the presence of intoxicants and / or user interference, is believed to offer a better chance of acceptance. The idea of ​​providing a system that includes a compliance detection mode as a normal operating mode and that is fast and easy for the majority of users and / or test situations, and that shifts to an interactive detection mode when necessary, is part of the inventive concept of the present invention. The interactive detection mode can be thought of as a special operating mode that requires user interaction and more time-consuming measurements / analysis and that is used for only a portion of all test cases.

[0038] FIG. 1a is a schematic diagram of the functional units of a breath analysis system 100 according to the present invention, comprising a breath measurement unit 12 with a measurement cell or cavity 12a into which a breath sample is drawn for analysis of its tracer and intoxicant content. The breath measurement unit 12 further comprises an inlet 12b connected to one end of the measurement cell 12a and an outlet 12c connected to the other end. The breath measurement unit 12 typically also comprises a fan for directing airflow through the measurement cell and one or more heaters for raising and controlling the temperature of the incoming air. The breath measurement unit 12 provides an estimate of one or more intoxicants associated with the user. The breath measurement unit 12 may be referred to as a primary detection unit because the output from this device is important for further analysis and represents a measure of how a decision is made. Other primary detection units, such as a biometric detector used to verify the user's identity, may also be present in the vehicle. One or more visual attractors 13 may be provided near the inlet 12b of the breath measurement unit 12. The visual attractors 13 are provided to attract the user's attention so that the user turns toward the visual attractors 13 and then toward the inlet 12c of the breath measurement unit 12. According to one embodiment, the visual attractors 13 are LEDs configured to light up during breath sampling. Alternatively, the visual attractors 13 may be a representation or illustration on an existing display, such as an arrow pointing toward the inlet 12c, which is displayed on the existing display during breath sampling.

[0039] The breath analysis system 100 may further include at least one secondary detection unit 14. The secondary detection unit 14 is configured to provide other information about the user than the primary detection unit. Examples of secondary detection units 14 include, but are not limited to, a camera 14a combined with image analysis capabilities, a microphone 14b combined with voice recognition capabilities, an IR sensor 14c, and a seat occupancy sensor (not shown). The secondary detection units 14 may be used alone or in combination to provide information about how the user is complying with the instructions provided by the breath analysis system, and further to provide other information that may be useful for analysis, such as the presence and location of occupants within the vehicle compartment.

[0040] The breath analysis system 100 may further comprise at least one dialogue unit 15 used by the system to communicate instructions to the user and may be further configured to receive responses from the user. Examples of dialogue units 15 include, but are not limited to, a loudspeaker 15a combined with speech generation capabilities, a display 15b capable of displaying instructions as text messages, images, videos, and animations. The display 15b may be a touchscreen that further allows input from the user. Alternatively, other known types of input units may be provided, such as a unit for voice recognition.

[0041] The measurement unit 12, secondary detection unit 14, and interaction unit 15 are connected to a central processing unit (CPU) 11, which controls the connected devices and receives and processes input signals or data from the devices. The breath analysis system 100 may further include a wired or wireless communication unit 16 for communication with external entities or other systems in the vehicle. A long-term memory functioning as a digital library 17 connected to the CPU 11 may be provided, in which various messages, images, or videos are stored so that they can be selected by the CPU 11 to provide different instructions to the user. A program memory 18 is typically included to store the system's operating sequences. As will be appreciated by those skilled in the art, means for storing data, parameters, and instructions can be provided in many different ways, and the use of the digital library 17 in combination with the program memory 18 should be considered a non-limiting example of a suitable memory configuration. A power supply unit 19 is provided to provide power to all units / devices of the system. Alternatively, the units / devices of the system can be powered by the vehicle's common power system.

[0042] As will be appreciated by those skilled in the art, many of the described units and devices of the breath analysis system 100 are already present in the infotainment systems of modern vehicles. Examples include loudspeakers, microphones, means for voice recognition / generation, and various displays in the audio system. Therefore, an obvious design choice is to "reuse" as much existing equipment as possible rather than duplicating specific devices. According to one embodiment, the breath analysis system 100 is integrated into the vehicle's infotainment system and at least the CPU, with the power supply and audio system being parts used by both the infotainment system and the breath analysis system 100. Some of the above-described units are not necessarily independent units; for example, a voice recognition unit is typically a function or application running on the CPU or another processing unit. Those skilled in the art will recognize that the above-described units and functions may be implemented in different ways, and that the selection of specialized or multi-purpose hardware with different functions provided by software or firmware will be made taking into account the teachings of the present invention and the constraints and possibilities enabled by a particular implementation. Therefore, the design of a system may be significantly different for a stand-alone system, such as a breath analysis system that "stands alone" in providing all of the above functions, compared to a system mounted on a vehicle that includes many of the audiovisual communication facilities already present in the vehicle.

[0043] An exemplary embodiment of a breath analysis system according to the present invention is shown diagrammatically in FIG. 1b, which shows a dashboard 20 of a vehicle, for example a car. The system is located on and integrated into the dashboard 20 and steering wheel 21. An inlet 12b of the breath measurement unit 12 is provided near the center of the steering wheel 21, and a light source is located in close proximity to the inlet 12b to serve as a visual attractor 13. A secondary detection unit 14 is provided in the dashboard 20 in the form of a camera 14a and a microphone 14b, and is adapted to monitor signals related to the driver's behavior. An interaction unit 15 including a loudspeaker 15a and a display 15b, for example a touchscreen, is further provided in the dashboard 20.

[0044] A method according to the present invention for determining a restriction level for a user performing a specified task, typically a driver attempting to start and drive a vehicle, is shown in the flowchart of FIG. 2. A breath analysis system 100, described with reference to FIGS. 1a-1b, is configured to perform the steps of the method. The method includes two distinct operating modes: a compliance mode and an interactive mode. The compliance mode is designed to be quick and not require any specific action from the driver beyond sitting in the driver's seat and breathing normally, which typically represent basic instructions that all drivers should be aware of. If the driver is not intoxicated and complies with these basic instructions, breath analysis can be performed in less than 10 seconds, preferably within 5 seconds. Therefore, as described above, the method of the present invention should operate in compliance mode for the majority of test situations. Interactive mode operation is only engaged when required, i.e., when breath analysis cannot be performed correctly in compliance mode. For example, the reasons are as follows. The concentration of intoxicating substances in exhaled breath is close to the permissible limit, but the uncertainty in the estimated measurement appears to be too large to allow a conclusive classification of the driver. The breath analysis cannot be carried out due to the driver obstructing the procedure. The inability to perform breath analysis due to malfunction of measuring equipment. The inability to perform breath analysis due to obstructions within the vehicle compartment, such as an occupant with alcohol-containing breath, an open window on a windy day, and the presence of substances that interfere with breath analysis. Any ambiguity in the available data, which may include both breath analysis data and input from the secondary detection unit 14.

[0045] The interactive mode may take significantly longer than the compliance mode. However, some methods according to the present invention may require incrementally more interactive responses from the user, and thus the time required to perform the classification may also be incrementally increased. For example, an initial failure to perform the classification may result in an action being issued to the user that is relatively quick to perform, typically on the first attempt.

[0046] Part of the operation of the interactive mode is to establish an action adherence value that must exceed a minimum requirement to enable classification of the user's driving ability in terms of a regulatory level. A session history log containing data recorded during the session is used as a tool to determine the updated version of the action adherence value. The session history log includes information about selected actions taken in the current interactive mode session and the corresponding results of the selected actions taken, and the action adherence value is a value determined from the results of the selected actions taken.

[0047] At the start of the interactive mode of operation, the action adherence value is quantified below a required threshold to enable classification into a restriction level. By providing more detailed instructions and requests and obtaining more data, the action adherence value is updated based on this data. The calculated updated action adherence value may determine the user's driving ability in terms of the applicable restriction level. The contents of the session history log are obtained using recorded data from sensor signals during the session, from which the action adherence value is calculated.

[0048] The method according to the invention uses two sets of parameters and / or instructions, the contents of which have been previously provided and stored: The set of restriction levels may include restriction levels such as "driving without restrictions," "driving with a warning issued," "restricted driving capability," and "ignition locked." A particular restriction level may be selected based on the user's measured breath concentration of an intoxicant, e.g., a first concentration interval corresponds to a first restriction level, and a second concentration interval corresponds to a second restriction level. The concentration intervals may correspond to legal levels of one or more intoxicants and may further take into account physiological aspects, such as whether the subject is in the absorption or excretion phase of substance concentration dynamics. Additionally, in interactive mode, non-compliance with issued instructions may influence the selection of a restriction level, such that a restriction level that restricts driving capability is selected even if classification cannot be performed. Furthermore, if the intoxicant breath concentration is measured within the first interval, a higher restriction level may be selected, e.g., when non-compliance is determined based on input from the secondary detection unit 14. The set of predetermined actions includes, for example, the following actions: Enable visual cues. Give instructions such as "Please face the detector" and "Please lean forward. Face the detector and exhale into entrance 12b." They issue warnings such as, "There is still insufficient data. If the situation does not improve, your driving may be restricted or you may be suspended." The content may vary depending on the implementation of the system and method, for example, as an adaptation to variations in the availability of secondary detection units 14 and / or the type of interaction unit 15. Thus, the method according to the invention is adaptable to different hardware configurations, typically only requiring updating the content of the set. Furthermore, how the actions are performed in detail depends on the hardware configuration and the equipment in the vehicle. For example, an ignition lock may be provided as a separate existing function in the vehicle, or an equivalent locking effect may be provided by other means.

[0049] The compliance mode of operation according to the method of the present invention comprises: 200: Sampling a signal representative of a local concentration of an intoxicant, analyzing the results of the sampling, and determining from the results of the analysis whether the breath concentration of the intoxicant of the user can be classified with a required level of accuracy and precision; 205: If classification is determined to be feasible, 205:1: Determining an intoxicant breath concentration; 205:2: comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; Including, 210: If it is determined that classification is not possible to perform, the method enters an interactive mode of operation.

[0050] Interactive mode behavior is 215: Issuing an action selected from a set of predetermined actions to the user, the selection of the instruction being based on the session history log and the action adherence value; 220: Sampling a signal representative of a local concentration of an intoxicating substance, analyzing the results of the sampling, and determining from the results of the analysis whether the breath concentration of the intoxicating substance of the user can be classified with a required level of accuracy and precision; 225: If classification is determined to be possible, 225:1, determining an intoxicant breath concentration; 225:2: comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; If classification is deemed impossible, 230: Determining an action compliance value based on an analysis of how well the user complies with the issued selected action; 235: Updating a session history log, the session history log including information about which actions of a predetermined set of actions have been issued; 240: Repeating the steps (215 to 235) in the interactive mode until a regulation level is established or until a predetermined maximum period is reached; Includes.

[0051] The steps of determining whether classification is possible (steps 205 and 225) should be interpreted as meaning that it is possible to measure the concentration of an intoxicating substance in the user's exhaled breath with acceptable accuracy and precision, and to classify the concentration as being above a predetermined level, typically a legal level, below a predetermined level, or within a predetermined interval. Acceptable accuracy / precision can typically, and preferably, be determined by statistical analysis of sampled data, typically further combined with knowledge of known error levels and predictable fluctuations in the breath analysis system, such as temperature dependence. Due to the importance of accurate classification, it is crucial that the complete measurement process be performed in a manner that provides a high degree of certainty in the concentration measurement. It may also be appropriate to include a "safety margin" in using the measurement results to determine regulatory levels, for example, to consider the fact that a specific concentration determination at a given time point may become invalid after a certain period of time, depending on whether the subject is in the absorption or elimination phase of substance concentration dynamics. This is particularly important when legal limits are low, such as in Sweden. The typical duration of the absorption phase is 30 minutes over a wide range of alcohol concentrations. Elimination is typically linear with respect to time, but may vary significantly from person to person. Typically, one centiliter of pure alcohol is metabolized per hour.

[0052] Those skilled in the art will be able to implement appropriate measurement systems and measurement schemes given the level of accuracy and precision required. Co-pending application SE2050105-2, by the same applicant as the present invention, provides a particularly time-efficient system and method for performing accurate and highly precise measurements and classifications.

[0053] According to one embodiment, the intoxicating substance is alcohol and the measurement performed by the breath analysis system is a BrAC measurement (BrAC - breath alcohol concentration). A preferred method is a tracer gas measurement based system as described for example in US Patent No. 7,919,754 and US Patent No. 9,746,454.

[0054] According to one embodiment, the set of restriction levels includes multiple actions or settings representing increasing restrictions on the drivability of the vehicle. The set of restriction levels may include issuing a warning to the user, placing the vehicle in a restricted drivability mode, and locking the ignition. One restriction level should typically represent completely unrestricted use of the vehicle, which is used when the method enters an interactive mode of operation, and further steps result in the user complying with the given instructions and the concentration of any intoxicating substance being below the minimum legal limit. According to one embodiment, the set of restriction levels includes no restriction on use of the vehicle and at least one of the following: issuing a warning to the user, placing the vehicle in a restricted drivability mode, and locking the ignition. Depending on the method and the nature of the restriction level determined by the breath analysis system 100, the result, such as locking the ignition, may be communicated to other systems / functions of the vehicle. The result may also be communicated to an external entity, such as a fleet management system.

[0055] According to one embodiment, the set of predefined actions includes a number of actions that may be grouped according to the following: For example, attention actions that activate visual attractors 13; For example, an instruction action using the dialogue unit 15 to issue an instruction such as "Please turn your face towards the detector" A request for action, for example, encouraging the driver to lean forward towards entrance 12b, combined with a message stating that driving ability restrictions may be imposed if the user does not comply; A warning action, for example, using the dialogue unit 15 to issue a warning such as "Your driving ability has not been verified due to insufficient data."

[0056] According to one embodiment, determining the action adherence value includes evaluating the results of sampling, where improved classification support results in a high action adherence value, even if the sampling results are still not suitable for final classification. Determining the action adherence value may include evaluating secondary input data, which is typically data received from one or more of the secondary detection units 14. The secondary input data may include video or images, signals from IR sensors (to detect the presence of a user or passenger), and seat occupancy sensors. User behavior is analyzed and classified from video and / or image analysis or other signals, or a combination thereof. Analysis may range from establishing the user's presence to advanced image processing to recognize the presence of multiple people in the vehicle and their activities.

[0057] According to one embodiment, a further step is introduced which is performed when a selected action, typically a warning action, is issued, which further step involves the user acknowledging that he or she has understood the warning, and the system receiving, and preferably storing, such acknowledgment. In the same way, the user may be requested to acknowledge compliance with the restriction in a step which is performed after the restriction has been issued. The acknowledgment may be entered into the system via the dialogue unit 15.

[0058] According to one embodiment, the action adherence value determined in step 230 is based on an analysis of whether the intoxicant measurement improved the likelihood of classification to a predetermined level of certainty.

[0059] According to one embodiment, the interactive mode of operation includes using at least one secondary detection unit 14. The secondary detection unit 14 provides a user compliance input that is used in step 230 to determine an action compliance value. The action compliance value may be based on both the further user compliance input and the change (predicted improvement) in the intoxicant measurement results. The user compliance input provided by the secondary detection unit 14 may be, for example, an image provided by a camera 14a combined with an image analysis function, possibly indicating whether the user complied with instructions, such as facing the detector. The action compliance value is preferably parameterized to a set of integer values. One example is to include three values, where value 1 corresponds to a user not complying with the instructions for the selected action, value 2 corresponds to a user who partially complies with the instructions, and value 3 corresponds to a user who fully complies with the instructions. The value may be determined by image or video analysis, e.g., in the instruction "Bend toward the entrance," a value of 1 indicates the user intentionally directing their breath away from the sensor, a value of 2 indicates directing their breath toward the entrance, and a value of 3 indicates the user actually bending toward the entrance. Such image / video analysis can be implemented by those skilled in the art using existing methods. The analysis is not limited to the use of only one secondary detection unit 14. For example, inputs from a camera 14a combined with image analysis capabilities, a microphone 14b combined with voice recognition capabilities, an IR sensor 14c, and a seat occupancy sensor in various combinations may be beneficially used to analyze user behavior after an action is issued and to provide an action compliance value. It should also be understood that the action compliance value typically depends on the issued instruction and also on the session history log.

[0060] The session history log, which includes a list of selected actions issued and corresponding action compliance values, may typically be stored in program memory 18. In one embodiment, the session history log is updated for each session, such as a driving session or a single entry into a restricted area. In one embodiment, the history session log is maintained for a predetermined period of time, such as 30 minutes, to prevent a user from interrupting the vehicle's startup procedure in an attempt to manipulate the system. Such a feature is preferably combined with a user identification mechanism, so that the history session log is reset when the user changes. When the subject's identity is known from any available data source, the compliance value may be personalized by comparing the actual compliance status with the subject's usual behavior, available from previous session history logs.

[0061] According to one embodiment of the present invention, at least one secondary detection unit 14 is enabled in compliance mode, and if information available from the secondary detection unit 14 indicates tampering using breath analysis, the compliance mode is stopped and the method proceeds directly to the interactive mode.

[0062] According to one embodiment of the present invention using the breath analysis system 100 described with reference to FIGS. 1a and 1b, the interactive mode of operation includes: 215': issuing a selected action to the user from a set of predetermined actions, the selection of the instruction being based on the session history log and the action adherence value, and the selected action being issued via the visual attractor 13 and / or the interaction unit 15; 220': sampling a signal from the breath measuring unit 12 representing the local concentration of the intoxicant, analyzing the results of the sampling, and determining from the results of the analysis whether the breath concentration of the intoxicant of the user can be classified with a required level of accuracy and precision; 225': If it is determined that classification can be carried out with the required level of accuracy and precision, 225:1': determining the breath concentration of an intoxicant; 225:2': comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; If classification is deemed impossible, 230': determining an action compliance value based on an analysis of how well the user complied with the issued selected action using input from at least one secondary detection unit 14, the secondary detection unit providing other information about the user different from the breath measurement unit 12; 235': updating a session history log, the session history log including information about which actions of a predetermined set of actions have been issued; 240: Repeating the steps (215 to 235) in the interactive mode until a regulation level is established or until a predetermined maximum period is reached; Includes.

[0063] According to one embodiment, the selected action issued in step 215' involves the breath analysis system 100 using one or a combination of interaction units 15, typically and preferably a loudspeaker 15a combined with voice generation capabilities, a display 15b that may display instructions, for example as text messages, images, videos, and animations. The display 15b may be a touch screen that further allows for input from the user.

[0064] According to one embodiment, determining the action compliance value at which the selected action was issued in step 230′ includes one or a combination of secondary detection units 14 such as a camera 14 a combined with image analysis functionality, a microphone 14 b combined with voice recognition functionality, an IR sensor 14 c, and a seat occupancy sensor.

[0065] According to one embodiment of the present invention, the step of selecting a restriction level from a set of predetermined restriction levels, i.e., step 205:2:, 225:2 / 225:2′, further comprises informing the user about the restriction level using one or a combination of the dialogue units 15.

[0066] The use of the system and method according to the present invention can be shown in terms of time consumption. The compliance detection mode must be completed within 5 seconds. The decision process in the interaction detection mode based on breath analysis sensor data and driver response / compliance can include the following four main phases (and their time windows from the start): ·Warning (0 seconds ~ 5 seconds) ·Instruction (5 seconds to 10 seconds) Action Request (10-20 seconds) ·Warning (20 seconds to 30 seconds)

[0067] The division levels into four main phases and timing is shown in Figure 3. An experienced, sober driver is typically approved within 3-5 seconds and allowed to drive without restrictions. If there is insufficient data, the driver receives detailed instructions on how to provide an acceptable breath sample before the vehicle's drivability is enabled. If there is still insufficient data for breath analysis after 10 seconds, a request for action is issued with repeated, more detailed instructions. If there is still insufficient data after 20 seconds, a warning is issued. The final drivability decision, i.e., restriction level, is issued after 30 seconds in this scenario.

[0068] The above-described embodiments are to be understood as illustrative examples of the system and method of the present invention. It will be understood by those skilled in the art that various modifications, combinations, and changes may be made to the embodiments. In particular, different partial solutions in different embodiments may be combined into other configurations, if technically possible.

Claims

1. 1. A method for operating a breath analysis system (100) to determine a level of restriction for a user performing a designated task based on an analysis of a concentration of an intoxicant in the user's exhaled breath and the user's behavior, the method comprising a compliance mode of operation and an interactive mode of operation, the method using a set of predetermined restriction levels and a set of predetermined actions; The compliance mode is (200) sampling a signal representative of a local concentration of an intoxicating substance, analyzing the results of said sampling, and determining from the results of said analysis whether said breath concentration of an intoxicating substance of said user can be classified with a required level of accuracy and precision; (205) If it is determined that classification can be carried out, (205:1) determining the breath concentration of an intoxicant; (205:2) comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; Including, (210) If it is determined that classification is not possible, the method enters into an interactive mode of operation, which includes: (215; 215') issuing a selected action from a set of predetermined actions to the user, wherein the selection of an instruction is based on a session history log and an action compliance value, the session history log including information about the selected action issued in a current interactive mode session and a corresponding outcome of the selected action issued, and the action compliance value being a value determined from the outcome of the selected action issued; (220; 220') sampling a signal representative of a local concentration of an intoxicating substance and analyzing the results of said sampling to determine from the results of said analysis whether said breath concentration of an intoxicating substance of said user can be classified with a required level of accuracy and precision; (225; 225') If it is determined that classification is possible, （２２５：１； 225:1′) determining the breath concentration of the intoxicant; （２２５：２； 225:2') comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; If classification is deemed impossible, (230; 230') determining an action compliance value based on an analysis of how well the user complied with the selected action issued, using input from at least one secondary detection unit (14) that performs detection to provide information about the user's behavior with respect to the selected action, or whether the measurement of the intoxicating substance improved the possibility of classifying it with the required level of accuracy and precision; (235; 235') updating said session history log, said session history log including at least information about which actions of said set of predetermined actions have been issued; (240; 240') repeating the steps (215 to 235) of the interactive mode until a restriction level is established; Including, method.

2. The method of claim 1 , wherein the set of restriction levels includes a plurality of restriction levels representing different levels of restrictions on operation of the vehicle.

3. 3. The method of claim 2, wherein the set of restriction levels includes one or more of the restriction levels corresponding to settings of the vehicle: driving without restriction, driving with a warning issued, restricted driving, and ignition lock.

4. 2. The method of claim 1, wherein the set of predetermined actions includes at least one of the following subsets: an attention action to attract the user's attention, an instruction action to instruct the user to turn their face towards the breath measuring unit, a request action to prompt the user to bend forward towards the entrance of the breath measuring unit, and a warning action to issue a warning to the user.

5. The method described in claim 4, wherein the attention action includes activating a visual attractor (13).

6. 6. The method according to claim 4 or claim 5, wherein a dialogue unit (15) is used by the breath analysis system (100) to communicate the action to the user.

7. 7. The method of claim 1, further comprising a further step that occurs when a selected action is initiated, said further step comprising receiving an acknowledgement from the user acknowledging understanding and consent to the selected action.

8. 8. The method according to any one of claims 1 to 7, wherein the action compliance value determined in step (230; 230') is based on an analysis of whether the measurement of the intoxicating substance improves the likelihood of classification with the required level of accuracy and precision.

9. The interactive mode of operation includes: (215') issuing a selected action to the user from a set of predetermined actions, wherein the selection of an instruction is based on the session history log and the action adherence value, and wherein the selected action is issued via a visual attractor (13) and / or a dialogue unit (15); (220') sampling a signal from the breath measuring unit (12) representative of said local concentration of an intoxicating substance, analyzing the results of said sampling, and determining from the results of said analysis whether said breath concentration of an intoxicating substance of said user can be classified with a required level of accuracy and precision; (225') If it is determined that classification can be performed at the required level of accuracy and precision, (225:1') determining the breath concentration of the intoxicant; (225:2') comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; If classification is deemed impossible, (230') determining an action compliance value based on an analysis of how well the user complied with the issued selected action using input from the at least one secondary detection unit (14); (235') updating the session history log, the session history log including information about which actions of the set of predetermined actions have been issued; (240') repeating the steps (215-235) of the interactive mode until a restriction level is established; The method of claim 1 , comprising:

10. 10. The method of claim 9, wherein the step (215') of issuing the selected action includes the breath analysis system (100) using one or a combination of the interaction unit (15), i.e., a loudspeaker (15a) and a display (15b).

11. 10. The method of claim 9, wherein the step of determining (230′) an action compliance value after the selected action is issued includes using one or a combination of the secondary detection units (14), i.e., a camera (14a) combined with image analysis functionality, a microphone (14b) combined with voice recognition functionality, an IR sensor (14c), and a seat occupancy sensor.

12. The method according to any one of claims 1 to 11, wherein the repetition of the steps (215-235) of the interactive mode is terminated when a predetermined maximum period is reached.

13. A breath analysis system (100) comprising a breath measurement unit (12), at least one visual attractant (13), at least one secondary detection unit (14), at least one interaction unit (15), and a CPU (11), wherein the breath analysis system (100) is configured to provide a compliance mode, the compliance mode comprising: (200) sampling a signal from said breath measuring unit (12) representative of the local concentration of an intoxicant, analyzing the results of said sampling, and determining from the results of said analysis whether the breath concentration of said intoxicant of said user can be classified with a required level of accuracy and precision; (205) If it is determined that classification can be carried out, (205:1) determining the breath concentration of an intoxicant; (205:2) comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; Including, (210) If it is determined that classification is not possible to perform, an interactive mode of operation is provided, the interactive mode of operation comprising: (215') issuing a selected action to the user from a set of predetermined actions, wherein the selection of an instruction is based on a session history log and an action adherence value, and the selected action is issued via the visual attractor (13) and / or the dialogue unit (15); (220') sampling a signal from the breath measuring unit (12) representative of the local concentration of an intoxicating substance, analyzing the results of said sampling, and determining from the results of said analysis whether the breath concentration of said intoxicating substance of said user can be classified with a required level of accuracy and precision; (225') If it is determined that classification can be performed at the required level of accuracy and precision, (225:1') determining the breath concentration of the intoxicant; (225:2') comparing the intoxicant breath concentration with a set of predetermined concentration intervals to select a restriction level from a set of predetermined restriction levels, each of the predetermined concentration intervals corresponding to a predetermined restriction level; If classification is deemed impossible, (230') determining an action adherence value based on an analysis of how well the user adheres to the issued selected action using input from at least one secondary detection unit (14), the secondary detection unit performing detection to provide information about the user's behavior with respect to the selected action; (235') updating the session history log, the session history log including information about which actions of the set of predetermined actions have been issued; (240') repeating the steps (215-235) of the interactive mode until a restriction level is established; Including, The breath analysis system (100).

14. The system of claim 13, wherein the secondary detection unit (14) is one or a combination of a camera (14a), a microphone (14b), an IR sensor (14c), and a seat occupancy sensor.

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